CVE-2026-46355CWE-287

CVE-2026-46355

High · published August 21, 2026

CVSS v3.1
7.1
EPSS
0%
Percentile
29.7
In the wild
Unconfirmed
What it is

BigBlueButton is an open-source virtual classroom. Prior to 3.0.23, BigBlueButton exposed /bigbluebutton/api/handleJoinExistingUser through bigbluebutton-web/grails-app/controllers/org/bigbluebutton/web/controllers/ApiController.groovy. A requester able to supply an existingUserID for an active participant could reuse that participant's session and impersonate the participant in the same meeting because handleJoinExistingUser was a routable controller action rather than a private helper. This issue is fixed in version 3.0.23.

The record
Technical detail
CVSS v3.1
7.1 · HIGH
Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:N
CVSS v4.0
Not supplied
EPSS
0.00370 · 29.7th percentile
Weakness
CWE-287 · Improper Authentication
Published
2026-08-21T02:17Z
References (3)
https://github.com/bigbluebutton/bigbluebutton/commit/972b04e474e195cbd708b5b3f0485fe528a1a85b · [email protected]https://github.com/bigbluebutton/bigbluebutton/releases/tag/v3.0.23 · [email protected]https://github.com/bigbluebutton/bigbluebutton/security/advisories/GHSA-38fw-2gq7-ccgr · [email protected]
EPSS history
Timeline
  • 20 AUG 21:34Z
    BigBlueButton: Unauthenticated Session Hijack via Exposed /bigbluebutton/api/handleJoinExistingUser
    cvelistv5